Detailed
Information:
"5mm LEDs? With Luxeons dominating
the market for bright LED lights? How old fashioned!"
Funny how bright white 5mm LEDs just came out a few
years ago, and yet those of us who keep up with the
industry tend to view them as almost "out of date"
with the Luxeon high-flux LEDs gaining ground. Well,
the Corona is a reminder that white 5mm LEDs are here
and they are here to stay.
The "body" of the Corona consists of 3 parts:
the bezel, the battery box, and the straps.
Starting at the front, you will find an
odd shaped polymer bezel which contains several important
features. First, it is sealed for water entry to 1 meter
depth. Essentially, it is rainproof and a dunk in the
pond won't bother it either. The very front of the unit
sports 8 white 5mm LEDs in a dull gray reflector. LED
are by nature very impact resistant, so no blown bulbs
to worry about with the Corona. The reflector has been
shaped around the various LED "banks" to enhance
the beam pattern depending upon which output level you
select. All of this is protected behind a polycarbonate
lens. The bezel is attached to the forehead plate via
a hinge which allows the bezel to be smoothly tilted
more than 90 deg. for vertical adjustment of the light
beam.
On top are the two switches which control
your output modes. The larger, flat switch controls
the number of LEDs you will be working with. The first
click gets you all 8 LEDs. Second click shuts off the
top bank of 3 LEDs, giving you 5 on. Third click turns
off the 5 bottom LEDs and turns on the top 3 again.
Finally, the last click turns off all but the bottom
one. Another click starts the cycle again. Pausing during
any part of the cycle for more than 5 seconds causes
the headlamp to turn off with the next click.
So what is that smaller, wart inflicted
button for? That allows you to select high, low or blink
mode for each of the LED modes mentioned. Want lots
of light, but don't want to kill your batteries? Pick
a bright mode and kick in the power savings option!
The low mode provides 40%-50% of the light of the high
mode, but uses only 25%-30% of the power of high mode.
Less light, but a significant increase in runtimes.
How is all this possible? Through the
use of a current regulated power supply inside the head
of the light which provides non-flickering dimming of
the LEDs as well as constant output from the LEDs over
the life of the batteries. Up until now, dimming modes
usually were achieved in better headlamps with PWM regulators.
These regulators flicker the LEDs very rapidly to create
the illusion of dim light. A much better solution than
using resistors, the PWM dimming made it look like you
were in a disco full of strobe lights if you moved quickly
or were trying to read a book. Current regulated dimming
results in no flicker; just a smooth flow of dimmer
light.
Now one of the big issues with LEDs of
any sort is that they produce heat when you push them
pretty hard. This heat isn't felt at the front of the
light like with incandescent lights, but it builds up
inside the LEDs. If you don't get rid of the heat, damage
can result. To solve this problem, Princeton Tec has
added an aluminum heatsink to the back of the bezel,
yet maintained the watertight integrity of the casing!
It's about time someone figured out how to do this!
The excess heat created by running the LEDs on their
bright modes is dumped to the heatsink and safely removed
to the environment. There is a plastic guard behind
the heatsink and it would be smart to leave it in place.
On "high" mode the heatsink can reach 170
deg F. which is hot enough to burn skin.
Output is in the form of a wide flood
of bluish tinted light. Pretty typical of 5mm white
LEDs. Great for close to medium range work.
# of LEDs
|
Level
|
|
|
8
|
high
|
200 (14.14)
|
2310 (23.10)
|
|
low
|
94 (9.70)
|
1050 (10.50)
|
5
|
high
|
122 (11.05)
|
1319 (13.19)
|
|
low
|
58 (7.62)
|
629 (6.29)
|
3
|
high
|
77 (8.78)
|
823 (8.23)
|
|
low
|
38 (6.16)
|
408 (4.08)
|
1
|
high
|
26 (5.10)
|
238 (2.38)
|
|
low
|
13 (3.60)
|
119 (1.19)
|
All
throw readings are in Lux
at one meter. The numbers in parenthesis are for comparison
in the Comparison
Charts.
I'm not even going to bother with the
advertised runtimes, since Princeton Tec considers the
end of the runtime when you can no longer read fine
print on a newspaper at 6 inches. I really wish they
would have stated the runtimes to the point where the
LEDs drop out of regulation like they did with the EOS
headlamp. I will mention that in the documentation
it states that regulated runtime on high will be relatively
short - 5 to 30 minutes - diminishing thereafter. Dim
mode greatly extends the constant output runtimes. It
also states that using lithium AA batteries will allow
the dim-8 LED mode to last about 12-16 hours!
Lithium AA? You bet! The Corona can run
on AA alkaline, L91 lithium AA, or rechargables. Using
lithium will extend runtimes relative to alkalines,
while rechargables will result in shorter runtimes.
The battery box is closed with an easy to use flip-clip.
No tools needed here, and no fumbling. Reverse polarity
protection is built in, so no worries about putting
the batteries in the wrong way. The box is sealed for
water resistance.
The battery box is connected to the bezel
via a cable with 2 clips on the headband and stress
grommets on each end. Positioned in the back, the batteries
help balance the headlamp for comfort.
I don't want to forget to mention a couple of other
little features. The straps are all attached to the
headlamp via slotted loops which allow the bands to
be easily removed for cleaning or replacement. The clips
on the side are made the same way. The elastic bands
are fully adjustable for size. .
What I Liked: Waterproof to 1 meter,
Tough/impact resistant, Current based regulation, Good
battery life, Bright, Easy battery change, Lightweight,
Accepts alkaline, lithium and rechargeable batteries,
Easy to use.
What I Didn't Like: Nothing.
Other Things I Noticed: There is
a warning in the box regarding Avalanche Beacons. It
states that the electronic controls in the light may
interfere with an avalanche beacon reciever set on or
near its maximum. It will not affect avalanche beacons
in transmit mode.
Conclusions: Fantastic close/medium
range headlamp. The only plastic headlamp out there
with a metal external heatsink to protect the LEDs from
damaging heat buildup and a current regulator circuit.
Bright modes allow for ample light, while dimmer modes
provide for very long runtimes. Load it up with lithium
batteries for even longer use and for good cold-weather
performance.
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